Abstract

Many encryption algorithms are proposed based on chaos and many of them have been shown to be successful because of the adapting nature of the traditional confusion-diffusion architecture. Still few problems have been identified. The plain image is not related with the cipher image which induces the chosen /known plain text attack. Further the keys used for the encryption is always fixed and is not chosen dynamically. In order to reduce these flaws, a novel chaotic encryption is proposed with dynamic keys selected from plain image itself. For the key generation, hyper chaos system is used along with the sum of the intensity values to encrypt the image with high security. The pixel change rate and changed intensity values are as high as 99.7123 and 33.4432 respectively which exhibit the resistance against chosen/known plain text attack. Simulations are performed for histogram analysis, correlation between adjacent pixels, entropy analysis and sensitivity analysis which reveals that the proposed scheme have good security which in turn can be adopted for secure communication applications.